Informed Visibility Mail Tracking & Reporting Machine Count

List of US Postal Service machines by site, including a description of each machine.

Automated Zone Indicator (AZI) Table

The AZI table lists each five-digit ZIP Code™ and is an indicator of the type of processing that typically takes place on letter mail destined for each ZIP Code. Each number in the file is a ZIP Code appended with a numeric zone indicator. The five numeric indicators are as follows:

1. Two Pass Zones: Automated two-step sector/segment at mail processing facilities
2. 876 Carrier Route Sort Zones: Automated incoming secondary carrier route sorting at plants
3. Carrier Route Barcode Sorter (CSBCS) Zones: Automated walk sequence sorting on CSBCS machines at delivery units
4. Delivery Barcode Sorter (DBCS) Zones: Automated walk sequence sorting on DBCS machines at plants [i.e., sectional center facilities (SCFs)] or at delivery units
5. Manual/Mechanized Zones: No automated sorting; no tracking code scans should be generated from facilities matched to these ZIP Codes

October 4 2026 - PO! and ProgReg - Release Notes

PROCESSING AND DISTRIBUTION - Chicago, IL Regional (RPDC) - Power Outage

API Access Control Customer Dispute Instructions

INFORMATIONAL - UPDATE: PostalOne! Alert – October 4, 2026

INFORMATIONAL - Commercial System Releases – October 7, 8, and 11, 2026

Undeliverable-as-Addressed (UAA) Statistics by Mailing Industry Quarterly Report (Q4 FY26)

ACS Nixie stats by industry for FY26 Q4.

Mail Service Provider (MSP) - Full-Service Certified Mailers

A Mail Service Provider (MSP) offers a variety of solutions to prepare and present Full-Service presort mailings. For more information regarding Certified MSPs, please follow this link: https://postalpro.usps.com/full-service-cert/fact-sheet

September 2026 Nixie Volume

This spreadsheet contains the UAA statistics for September 2026.